Watching it on a satellite picture the palace has a semicircular shape... why?? In this area 2000 years ago there were the bleachers of the Pompeus Theater, built at the time of Julius Ceaser.
Being the city of Rome built on layers, the foundations of the ancient theaters were “recycled” to hold the modern structures so the cellars of the building still have their structures in “opus reticolatus”, the construction technique dating back to the Roman times.
In 1100 a small church was built which was deconsecrated in 1926 and it has been used as a storage since then.
The Grottapinta building (“painted grotto”) is named after a small arch which links via del Biscione to via di Grottapinta where a fresco depicting the Virgin Mary used to be.
The fresco was moved in 1400 to the near church of Saint Lawrence in Damaso and replaced by a painting which has been stolen many times through the years.
That’s why in the 1960’s the gate was added and locked with a key which was given only to the elderly people living in the area, so that they could use the shortcut and avoid a long walk to go back home. But in Rome nothing is reserved to a few people: within a couple of weeks everybody could get a copy of the key and shortly the passage was not locked anymore and the painting has been stolen over and over again!